Method for Clearing Blockages in In-Situ Artificial Lumens

ABSTRACT

Devices and methods for the effective clearing of artificial tubes, especially in-situ clearing of artificial tubes in a living being are covered in this disclosure. An elongated clearing member includes either a fixed or an adjustable element that selectively defines the portion of the elongated clearing member that is insertable within the artificial tube. The proximal end of the clearing member is releasably secured to the driving mechanism and the driving mechanisms may comprise a wide variety of repetitive motion drivers such as voice coil motors, piezoelectric actuators, pneumatic actuators, DC motors, etc. These devices/methods may comprise a free-standing console for hands-free operation or may comprise hand-held versions. The distal working end of the clearing member may comprise tips of differing functions, including an irrigation/aspiration feature.

CROSS-REFERENCE TO RELATED APPLICATIONS

This continuation-in-part application claims the benefit under 35 U.S.C.§120 of U.S. application Ser. No. 12/274,937, filed on Nov. 20, 2008entitled FEEDING TUBE CLEANER which in turn claims the benefit under 35U.S.C. §119(e) of U.S. Provisional Patent Application No. 60/989,484,filed on Nov. 21, 2007 entitled FEEDING TUBE CLEANER and of U.S.Provisional Patent Application No. 61/099,737, filed on Sep. 24, 2008entitled DEVICE FOR CLEARING BLOCKAGES IN FEEDING TUBES and all of whoseentire disclosures are incorporated by reference herein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention was produced in part using funds from the Federalgovernment under National Science Foundation Award ID nos. IIP-0810029and IIP-0923861. Accordingly, the Federal government may have certainrights in the invention.

BACKGROUND OF THE INVENTION

1. Field Of Invention

The present invention generally pertains to cleaning or clearing devicesand methods of using such devices for the in-situ clearing of artificiallumens within a living being including the in-situ clearing of feedingtubes.

2. Description of Related Art

The following is a description of the background of feeding tubes. Itshould be understood that the device and method of the present inventionis not limited to the clearing of feeding tubes but is applicable to arange of artificial lumens such as indwelling catheters and that feedingtubes are being discussed simply by way of example.

A feeding tube is a medical device used to provide nutrition to patientswho cannot obtain nutrition by swallowing. The state of being fed by afeeding tube is called enteral feeding or tube feeding. Placement may betemporary for the treatment of acute conditions or lifelong in the caseof chronic disabilities. Varieties of feeding tubes are used in medicalpractice and are usually made of polyurethane or silicone.

A gastric feeding tube, or “G-tube”, is a tube inserted through a smallincision in the abdomen into the stomach and is used for long-termenteral nutrition. The most common type is the percutaneous endoscopicgastrostomy (PEG) tube. Feeding tubes may also be of the nasogastrictype commonly called “NG-tube”, which are introduced through the nose,down the esophagus and into the stomach in a procedure calledNasogastric intubation. PEG-tubes on the other hand are placedendoscopically: the patient is sedated, and an endoscope is passedthrough the mouth and esophagus into the stomach. The position of theendoscope can be visualized on the outside of the patient's abdomenbecause it contains a powerful light source. A needle is insertedthrough the abdomen, visualized within the stomach by the endoscope, anda suture passed through the needle is grasped by the endoscope andpulled up through the esophagus. The suture is then tied to the end ofthe PEG-tube that is to be external, and pulled back down through theesophagus, stomach, and out through the abdominal wall. The tube is keptwithin the stomach either by a balloon on its tip (which can be inflatedor deflated) or by a retention dome which is wider than the tract of thetube. In the case of NG-tubes, once they are passed through thepatient's nostril, a clinician must be careful not to accidentally slipthe end of the tube into the patient's lungs. Additionally, upon placingthe NG-tube in the patient's gastric system, for example the stomach, itis common for the tubes to slip as the primary securing means is to tapethe tube to the patient immediately outside the nostril. Clinicians maypass nutrients to the patient's stomach or remove fluids from thepatient via the lumen or NG-tube.

Approximately 410,000 PEG-tubes and 5 million NG-tubes are placed eachyear in the U.S. A down-side of the life-sustaining feeding tube is thatthey can become clogged. Based on a 35% clogging rate, US civilianmedical facilities, treat over 1.7 million NG clogs and 140 k PEG clogsannually.

Numerous conditions that may necessitate enteral nutrition over longperiods of time include but are not limited to traumatic injury orelderly illness such as Alzheimer's, Parkinson's, or Cancer. Whenlong-term enteral access is needed, gastronomy—(G), jejunostomy—(J) orgastrojejunal—(GJ) tubes are often surgically inserted. J- and GJ-tubesare employed when gastric complications are present and improvednutrient uptake is necessary. Therefore, the J-tube distal end ispositioned in the bowels. Reported clogging rates of GJ and J-tubes havebeen as high as 35% mainly due to the small bore, considerable length,and convoluted geometries of the tubes once placed. As the discussionbelow suggests, standard nursing protocols to clear tube occlusions aretime consuming at best and are often unsuccessful. GJ- and J-tubes areespecially challenging due to the curvature associated with placement.

When a patient's enteral feeding tube becomes clogged, the process ofclearing it can be time-consuming and expensive, especially if the tubemust be replaced. Additionally, a clog can interrupt the patient'ssupply of nutrients and cause him discomfort. Many nursing policiesrecommend flushing feeding tubes with water every four to six 5 hours,and before and after administering medications or checking gastricresiduals. Even with these policies, the rate of feeding tube occlusionis approximately 12.5%. Small-bore tubes are even more prone to cloggingthan are large-bore tubes, and clogging of these tubes has been shown tobe a major cause of feeding downtime. A patient with an occluded tubemay miss several hours of feeding and receiving nutrients before thetube is unclogged or replaced. This concern, along with patients'discomfort and the expense incurred by having to replace tubes thatcould not be unclogged, identifies problems to be corrected by thepresent invention.

Over time, feeding tubes become brittle and need to be replaced. A majorcause of this is the accumulation of fungus inside the feeding tube.Standard feeding tube maintenance is to “flush” feeding tubes withwater; however, this does not remove debris and fungus from the innerwalls. Once a tube clogs, it is prone to reclogging.

Medications are the number one reason for tubes getting clogged. Certainmedications, such as Metamucil or liquid pain reliever, build up on theinner walls of the tube and promote clogging. Other medications need tobe crushed and mixed with water. If these medications are not adequatelyflushed or crushed finely, they will clog the tube. Older patientsreceive an average of 8-11 medications regularly throughout the day. Dueto medical restrictions on fluid intake, or if the care-giver is rushed,an adequate flush may not occur. A clogged tube can leave an alreadycompromised patient without medication or nutrition for hours, or evendays, and is extremely frustrating to both the patient and thecaregiver.

Patients with long-term feeding tubes are generally cared for at home orin a long term nursing facility. Advancements in technology and homenursing have allowed the utilization of home enteral nutrition todramatically increase over the last few decades. While this is certainlypositive, the down side is that when a feeding tube becomes clogged suchthat it cannot be unclogged with conventional methods, the patient mustbe transported to a specialty hospital to have the tube surgicallyremoved and replaced. For persons recovering in rural areas, this couldbe even more problematic as an extensive car ride—several hours—may benecessary to reach the specialty hospital. This disruption is a timeconsuming, expensive, and agonizing experience for the patient andfamily members. Numerous hours without nutrients and medication couldhave significant adverse effects on recovery of wounded soldiers,elderly and chronically ill patients.

One product which claims the ability to assist in restoring feedingtubes by degrading the clogged matter is the CLOG ZAPPER™ availablethrough CORPAK® MedSystems of Wheeling, Ill. and is disclosed in part inU.S. Pat. No. 5,424,299 (Monte). This product relies on a chemicalsolution being injected into an enteral feeding tube to clear remnantfood from the tube and decontaminate the tube. The chemical solutionmixture comprises maltodextrin, cellulase, alpha-amylose, potassiumsorbate, papain, ascorbic acid, disodium phosphate, sodium laurylsulfate, disodium EDTA, and citric acid. While the solution providessome assistance in degrading the clogged matter, some patients may beallergic to at least one of these ingredients and the system forintroducing the chemical solution is not always successful.

The current state of science includes three approaches to remove a clog:(1) syringe flush, (2) chemical and enzymatic treatment, and (3)mechanical devices.

Syringe Flush

The most recommended approach is to use a ‘flushing syringe’. The firststep is to insert the syringe into the tube and pull back on the plungerto attempt to dislodge the clog. If not successful, warm water is placedinto the tube and pressure, alternating with syringe suction, isperformed. This may need to be repeated for up to 30 or more minutes.However, this may not always be done with enough efficiency orregularity and a high percentage of tubes remain clogged.

Chemical and Enzymatic Treatment

Chemical approaches to clog removal involve a nurse flushing the tubewith a variety of reported substances, such as enzymes, meat tenderizer,soda, and fruit juices. More recently developed chemical approachesinclude using a dose of pancrelipase (Viokase®) and sodium bicarbonatemixed with water. The Clog Zapper uses a syringe filled with anunclogging powder with a variety of ingredients. Product directionsstate to allow the solution to set for an hour before flushing the tube.The InTRO-ReDUCER is a catheter that allows the solution to beintroduced directly at the clog site, which has been reported to be moreeffective than introducing the solution at the external end of thefeeding tube. Chemical approaches to clog removal are not effective.Patients can also be allergic to the ingredients in the chemicalapproaches, or adversely affected by the high sodium content.

Mechanical Devices

Mechanical devices to remove clogs are also available. Tiny brushes onwires can be used to break up the clog, but have been reported to packthe material in some clogs even more densely. The Enteral Feeding TubeDeClogger® by Bionix is a plastic, flexible rod with a spiral tip on theend. The DeClogger can be twisted to break through or pull outobstructions. Even when successful, these approaches can take up to 30minutes to several hours per patient, do not leave the tube walls clear,and do not progress through tortuous paths well.

What is needed is an apparatus capable of mechanically breaking up theclogged material from the sidewalls and inner portions of indwellingartificial tubes and catheters, and especially enteral feeding tubes. Inaddition, a regular maintenance schedule is preferred for using theapparatus to clean the walls of the tube. This regular maintenancecleans the tube walls of debris while stopping potential nucleationsites in which new clogs can grow from.

All references cited herein are incorporated herein by reference intheir entireties.

BRIEF SUMMARY OF THE INVENTION

These and other features of this invention are described in, or areapparent from, the following detailed description of various exemplaryembodiments of this invention.

It is hereby noted that the term “in situ” is defined as performing anact on an element while the element is being utilized for its commonlyknown function. For example, performing the act of clearing a clog orblockage from a feeding tube in situ refers to cleaning or clearing aclog or blockage in a feeding tube while the feeding tube is connectedto the digestive system of a being, human or other.

It should be understood that it is the Applicant's belief that where theclearing member of the embodiments disclosed herein utilizes a brush orbrush function along any portion of the clearing member that makes anyentry into the artificial lumen, the clearing member also cleans thatinterior portion of the artificial lumen.

A device is disclosed for the in situ clearing of blockages inartificial tubes (e.g., feeding tubes, including pediatric feedingtubes, PEG-tubes, NG-tubes, GJ-tubes, NJ-tubes, etc.) completely orpartially disposed within a living being. The device comprises: acontroller that remains outside of the living being, and wherein thecontroller comprises an actuator (e.g., voice coil motor; DC motor;piezoelectric actuator such as amplified piezoelectric actuators andLangevin transducers; solenoid motor; pneumatic motor, etc.) forgenerating repetitive motion (e.g., reciprocating, rotating, etc.); aclearing member having a first end that is releasably coupled to theactuator and having a second working end that is insertable into anopening in the artificial tube; wherein the second working end has aportion that comes into repetitive contact with a blockage in theartificial tube for clearing the blockage therein, wherein the clearingmember comprises a flexible material that permits 5 the clearing memberto make repetitive contact with the blockage while the clearing memberis positioned within a straight portion or within a curved portion ofthe artificial tube.

A method is also disclosed for the in situ clearing of blockages inartificial tubes (e.g., feeding tubes, including pediatric feedingtubes, PEG-tubes, NG-tubes, GJ-tubes, NJ-tubes, etc.) completely orpartially disposed within a living being. The method comprises: 10coupling a first end of a releasably-securable flexible clearing memberto a controller and wherein the controller remains outside of the livingbeing; inserting a second working end of the flexible clearing memberinto an opening in the artificial tube; energizing the controller suchthat the flexible clearing member experiences repetitive motion (e.g.,reciprocating, rotating, etc.) and positioning the flexible clearingmember such that the second working end 15 of the flexible clearingmember comes into repetitive contact with the blockage for clearing theblockage therein; and wherein the flexible clearing member clears theblockage when positioned within a straight portion or within a curvedportion of the artificial tube.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

Exemplary embodiments of this invention will be described with referenceto the accompanying figures.

FIG. 1 is an isometric view of the control box and clearing stem of thepresent invention resting on a table;

FIG. 1A is an isometric view of the control box and clearing stem of thepresent invention disposed on another device support (e.g., a pole cart,bed, etc.), shown in partial, adjacent the patient;

FIG. 2 is a top plan view of another control box with the lid removed;

FIG. 2A is a cross-sectional view of the control box taken along line2A-2A of FIG. 2;

FIG. 2B is a top plan view of an alternate embodiment of the control boxof FIGS. 1 and 1A with the lid removed;

FIG. 3 is a side view of the clearing stem of the present invention;

FIG. 3A is a cross-sectional view of the clearing stem taken along line3A-3A of FIG. 3;

FIG. 3B is a partial view of the sheath depicting both integer andperiodic length markings;

FIG. 3C is a side view of an alternate clearing stem that is thepreferred embodiment of the present invention;

FIG. 3D is a cross-sectional view of the alternate clearing stem of FIG.3C taken along line 3D-3D of FIG. 3C;

FIG. 4 is top plan view shown in cross-section depicting the clearingstem inserted within an artificial lumen in a living being showing theclearing stem clearing a blockage and depicting the stem's radius ofcurvature;

FIG. 5A is a partial view of the clearing stem whose distal end includesa plastic clearing tip on the distal end of the wire;

FIG. 5B is a partial cross-sectional view of the clearing stem whosedistal end includes an alternative hollow cylindrical clearing tip onthe distal end of the wire including a tip compression spring (TCS);

FIG. 5C is a partial cross-sectional view of the clearing stem whosedistal end includes an alternative clearing tip on the distal end of thewire including a gripping or chopping mechanism;

FIG. 5D is a partial view of the clearing stem whose distal end includesan alternative clearing tip on the distal end of the wire includes awelded ball;

FIG. 6 is a partial view of the clearing stem whose distal end includesa brush mounted on the wire tip;

FIG. 7 is a partial view of the clearing stem whose distal end includesa brush mounted on the distal end of the sheath;

FIG. 8 is a partial view of the clearing stem whose distal end includesa brush mounted on the distal end of the sheath with bristles swepttoward the extreme distal end of the stem;

FIG. 9A is a top view of the tube depth-control collar;

FIG. 9B is a side view of the tube depth-control collar;

FIG. 9C is a cross-sectional view of the depth-control collar takenalong line 9C-9C of FIG. 9A;

FIG. 9D is a partial isometric view of a fixed tube depth-control collarwith the clearing stem inserted into a feeding tube;

FIG. 10 is a plan view of an exemplary voice coil motor (VCM) for use inthe present invention;

FIG. 10A is a cross-sectional view of the VCM taken along line 10A-10Aof FIG. 10;

FIG. 11 is a top plan view of another exemplary motor of the presentinvention with the lid removed and depicting a DC motor that drives ascotch yoke;

FIGS. 11A-1 IC depict a sequence of the scotch yoke operation of FIG.11;

FIG. 12 is a top plan view of another exemplary motor of the presentinvention with the lid removed and depicting an amplified piezoelectricactuator (APA);

FIG. 12A is a cross-sectional view of the APA control motor taken alongline 12A-12A of FIG. 12;

FIG. 12B is a cross-sectional view of Langevin transducer control motor;

FIG. 12C is a functional diagram depicting the first four overtones ofclearing stein motion introduced by the Langevin transducer;

FIG. 13 is a top plan view of another exemplary motor of the presentinvention with the lid removed and depicting a solenoid;

FIG. 13A is a cross-sectional view of the solenoid motor taken alongline 13A-13A of FIG. 13;

FIG. 14 is a top plan view of another exemplary motor of the presentinvention with the lid removed and depicting a pneumatic actuator;

FIG. 14A is a cross-sectional view of the control motor taken along line14A-14A of FIG. 14;

FIG. 15 is a cross-sectional view of the magnetic pattern used in theVCM showing driving members having opposite pole directions;

FIG. 16A is a partial end view of the drive side of the control boxdepicting a sealing diaphragm;

FIG. 16B is a partial end view of the drive side of the control boxdepicting an alternative clearing stem coupling and sealing diaphragmconfiguration;

FIG. 16C is a partial end view of the drive side of the control box ofFIG. 16 showing the clearing stem being engaged with the control box ofFIG. 16B;

FIG. 17A is a block diagram of the control box electronics for thereciprocating tube clearer (TCI) configuration;

FIG. 17B is an operational flow diagram of the microprocessor of thecontrol box electronics of FIG. 17A;

FIG. 18A depicts a hand-held version of the present invention showingthe handset being gripped by the operator and including a tube depthcontrol-collar on the clearing member;

FIG. 18B depicts an alternative hand-held version of the presentinvention;

FIG. 18C is a side view of the alternative hand-held version showing thehand grip in cross-section;

FIG. 19 is a cross-sectional view of the hand-held version of FIG. 18A;

FIG. 20 is a cross-sectional view of the DC motor using a planetary geartrain configuration;

FIG. 21 is a cross-sectional view of the DC motor using a compound geartrain configuration;

FIG. 22 is an enlarged cross-sectional view of the clearing member andits components;

FIG. 23 is an enlarged cross-sectional view of the distal end of theclearing member which uses a helical design;

FIG. 24 is an enlarged cross-sectional view of the push-button actuatedtube depth-control collar;

FIG. 25 is an enlarged cross-sectional view of a torque-limiter that isdesigned to slip once a certain applied torque is exceeded;

FIG. 26 is a cross-sectional view of the hand-held version of thepresent invention depicting the multi-nodal harmonics while the clearingmember is spinning;

FIG. 27 is a cross-sectional view of a prior-art hand-held device thatgenerates rotatable motion depicting undesired operation with only anodal point at the proximal end of the clearing stem;

FIG. 28 is a block diagram of the control box electronics for therotating tube clearer (TC2) configuration;

FIG. 29 is a partial isometric view of the distal end of the sheath ofthe tube clearers TCI and TC2 showing aspiration/irrigation ports;

FIG. 29A is a partial isometric view of the distal end of the sheath ofthe tube clearers TCI and TC2 showing aspiration/irrigation ports;

FIG. 29B is a partial isometric view of the distal end of the sheathshowing a lumen or wire that is hollow;

FIG. 29C is a partial isometric view of the clearing stein using only ahollow lumen or a wire only, without a sheath, effectively using theindwelling lumen as the sheath;

FIG. 29D is a partial isometric view of the distal end of the sheath ofthe tube clearers TCI and TC2 showing a very narrow hollow wire allowingaspiration/irrigation along sides of wire; and

FIG. 29E is a partial isometric view of the distal end of the sheath ofthe tube clearers TCI and TC2 showing a small sheath channel for a verynarrow hollow wire and a larger channel for aspiration/irrigation.

DETAILED DESCRIPTION OF THE INVENTION

The preferred embodiments of this present invention are illustrated inFIGS. 1-29E with the numerals referring to like and corresponding parts.

The present inventions are portable devices, as well as methods for suchdevices, for effectively removing, moving or breaking up a clog from theinternal portions of an artificial tube or catheter, enteral tube, andpreferably a feeding tube, including pediatric feeding tubes. The actionof removing clogs and clearing artificial tubes can also be referred toas a “maintenance action”.

As will be discussed in detail later, there are basically two types oftube clearers (TC) disclosed herein, both of which are mechanical tubeclearers. The first type of tube clearer TCI includes severalembodiments that generate reciprocating motion of a clearing member forremoving, moving or otherwise breaking up a clog in the artificial tube.This tube clearer TCI is preferred for use in nastrogastic (NG) feedingtubes, although it should be understood that TCI is not limited for onlyclearing NG feeding tubes. FIGS. 1-17B, 29, 29B, 29C, 29D and 29E aredirected to TCI.

The second type of tube clearer TC2 involves the generation ofrotational motion of a clearing member for removing, moving or otherwisebreaking up a clog. This tube clearer TC2 is preferred for use inpercutaneous endoscopic gastric (PEG) feeding tubes, although it shouldbe understood that TC2 is not limited for only dealing PEG feedingtubes. FIGS. 5A, 5D, 18A-28, and 29A-29D are directed to TC2.

Both types of tube clearers TCI and TC2 are unique to feeding tubeclearing and overcome major obstacles in critical and long-term caremedicine by clearing clogged feeding tubes quickly and efficiently. Aswill be discussed in detail later, the tube clearer TCI and TC2 canremove a clog much faster (e.g., in less than 6 minutes) and at a muchgreater success rate than other currently-available clearingmethodologies/devices, while at the same time, resulting in cleaner tubewalls. Existing methodologies/devices simply do not work at all, do notclear the clogs properly, or they take a considerable time to do so.

In both tube clearers TCI and TC2, an activation unit or controllerremains external to the artificial tube and therefore the patient. Theactivation unit or controller delivers energy to a clearing stem (alsoreferred to as a “clearing member”) which is inserted into theartificial tube and whereby the clearing stem destroys the clog (e.g.,clogs of food and/or ground medication, etc.) and cleans the tube walls.As a result, the activation units in these clearers TCI and TC2 arereusable devices and the clearing sterns are disposable. The clearingstems of TCI and TC2 operate in narrow tube diameters, through severalradial curves sufficient to reach, e.g., the bowel. Thus, the tubeclearers TCI and TC2 clear safely and with greater efficiency for NG-,PEG-, GJ- and NJ-tubes. Both tube clearers TCI and TC2 require nocomplicated set up, e.g., no tuning is required.

Reciprocating Tube Clearer TCI

As shown in FIG. 1, the tube clearer TCI comprises an activation unit(also referred to as the “control box” or “controller”) 1 which remainsexternal to the artificial tube 39 (see FIG. 4) being cleared, andtherefore is also external to the patient (not shown). The activationunit 1 delivers energy to a clearing stem 26 which clears as it movesthrough the tube inner lumen 41 of the indwelling artificial tube 39,destroying the clog 40 and clearing the walls of the artificial tube 39,viz., the tube inner lumen 41 walls. Where feeding tubes are beingcleared by the tube clearer TCI, the tube clearer TCI breaks up clogs offood and ground medication in a short time (e.g., less than 6 minutes).The reusable control box 1 includes a motor which drives (actuates) thedisposable clearing stem 26. The control box 1 is positioned andreleasably secured onto a table, tray, or nursing cart 38, such as shownin FIG. 1. Alternatively, the control box 1 can be positioned on a polecart 38A (see FIG. 1A), or bed rail or any other type of support that isadjacent, or which can be moved adjacent to the patient or living being.

As shown most clearly by way of example in FIG. 3A, the clearing stem 26comprises a wire 28 running concentrically through a sheath 30. The wire28 protrudes from the end of the sheath 30 and is actuated while thesheath 30 remains stationary and is secured to a non-moving portion ofthe control box 1. The motion at the wire tip 29 clears the occlusion orclog 40.

Control Box 1

As shown in FIGS. 2-2B, the control box 1 comprises a motor 14, driveelectronics 10, electrical connectors, wiring, and clearing stemconnectors. The control box 1 is preferably constructed of polymer,although metallic, rubber, or a combination of all three materials maybe used. The preferred polymer is flame-retardant ABS plastic, althoughother polymers such as polyurethane, polypropylene, and nylon, but notlimited to such, may be used for, among other things, their lightweightcomposition and structural integrity. Metals such as aluminum, titanium,steel, brass in sheet or machined form may also be used, especiallywhere certain motor technologies (e.g., amplified piezoelectricactuators (APAs)) are used; to maintain efficiency of APAs, thenon-moving portion of them needs to be effectively clamped or else toomuch deflection on the side that should be clamped will greatly reducethe APAs' efficiency; a metal control box provides sufficient rigidityto properly clamp. The control box 1 has a releasable securing mechanismsuch as rubber feet, mechanically actuated suction cup, screws, rubberstops, or magnetic feet, etc. that facilitates its use on a table ornursing cart. As such, the control box 1 remains portable but isstationary during use. The motor 14 drives a motor shaft 15 thatgenerates the reciprocating motion. It should be understood that FIG. 2Bdepicts the preferred control box 1 because it comprises a novelclearing stem-control box interface, as will be discussed in detaillater with regard to FIGS. 16B-16C. FIG. 2B also depicts, by way ofexample only, the use of a counter balance mechanism 14A to counteractvibration caused by the reciprocation of an actuating motor 14, as willalso be discussed later.

In another embodiment, the electronic circuit and componentry forexample power indicator 3, fault indicator 4, enable switch 72 can beincorporated into a membrane switch such as XYMOX Technologies, Inc.Model No. 54894.

Clearing Stem/Member and Connectors

The clearing stein 26 comprises a sheath 30 which is fed into theclogged artificial tube. The preferred sheath material ispolytetrafluoroethylene (PTFE) although other tube materials may also beused such as, but not limited to, nylon, polyvinyl chloride (PVC),polyurethane, polyethylene, polypropylene, fluoropolymer, Viton, Hytrel.As mentioned previously, within the sheath 30 is a wire 28, which isattached to the motor 14. The motor 14 supplies reciprocating (alsoreferred to as “oscillating”) motion to the wire 28, causing the wire 28and its wire tip 29 to reciprocate back and forth. As can be seen mostclearly in FIGS. 3-3A, the wire 28 protrudes beyond the end of thesheath 30, and into the clog 40 (FIG. 4) which causes the disruption ofthe clog 40. The length of the wire protrusion 28A beyond the end of thesheath 30 strongly impacts the effectiveness of the clearing. Inaddition, the roundness of the wire tip 29 strongly impacts the ease ofinsertion of the clearing stem 26 into the artificial tube 39.

The clearing stem 26 may comprise a length of 60 cm to 250 cm, butpreferably 180-220 cm, and most preferably, 203 cm. In addition, thewire 28 may comprise a flexible wire most preferably stainless steeltwisted wire, but could also be helical wrapped wire or a flexiblestainless steel wire encased in a polymer wrapping, such as shrink wrap.The wire 28 protrudes from the end of the sheath a distance of 0 to 13cm, but preferably 1 to 5 cm and most preferably 2.54 cm. The clearingstem 26 releasably secures to the control box 1 via a Luer clearing stemconnector 6.

It should be noted that that, alternatively, the wire 28 may be hollowto enable other features such as irrigation or aspiration of theartificial lumen, as will be discussed later.

FIGS. 3-3A depict the clearing stem 26 which uses a magnetic-based andLuer lock connection to the control box motor 14, a stem stiffener 31 ata proximal end of the clearing stem 26, the amount that the wire tip 29extends beyond the sheath 30 (referred to as the “protrusion” or “wireprotrusion”) 28A, a wire stop 27, and tube depth-control collar 22. Inparticular, the proximal end of the clearing stem 26 comprises aclearing stem magnet 33 and a Luer clearing stem fitting 32 (FIGS.3-3A). The control box 1 includes a Luer clearing stem connector 6(FIGS. 2-2A) along with a motor magnetic coupler 13 which itselfincludes an internal magnet 12 in the coupler bore. To releasably securethe clearing stem 26 to the control box 1, the clearing stem magnet 33is passed through the Luer clearing stem connector 6, through adiaphragm 9 and into the motor magnetic coupler 13 where the clearingstem magnet 33 and magnet 12 come into contact to form the magneticcoupling. The Luer clearing stem fitting 32 and Luer clearing stemconnector 6 are then engaged to form the Luer lock configuration.Advantages to this magnetic connector include: the omission of threads(which can suffer from stripping), the avoidance of any special tools tofacilitate connection, reduced occurrence of bio-contamination, and theavoidance of having to disassemble any portion of the control box 1 inorder to switch clearing stems 26. The design of the mechanicalcomponents and the strength of the two magnets 33/12 are critical toavoid detaching the clearing stem 26 when the motor 14 is reciprocating.By way of example only, the magnets 12/33 may comprise rare earthmagnets (e.g., neodymium) for holding the clearing stem wire 28 to themotor shaft 15. The appropriately-sized magnets may provide from 0.5 to3.0 lbs of holding force. The sheath is held fast to the control box 1by the Luer lock connector/receptacle combination. It should beunderstood that clamping of the sheath 30 needs to have a certain forceto secure the sheath 30, but not crush the sheath 30. The stiffness ofthe sheath 30 must be adequate to preserve the inner diameter crosssection during operation. This is necessary to ensure the wire 28 is notpinched by the operator and its motion impeded. The wire 28 must also beflexible enough to navigate a small radius of curvature, such as 2.54 cmradius, while maintaining operation, as can be seen in FIG. 4. Inparticular, FIG. 4 depicts a clog 40 blocking the tube inner lumen 41 ofan artificial tube 39 and wherein the clearing stem 26 navigates a tightradius of curvature, R, and clears the clog 40 which is located past theradius of curvature R. The magnets 33/12 may be cylindrical in shape andthe magnet 12 within the motor magnetic coupler 13 is recessed withinthe motor magnetic coupler 13 that fits over the motor shaft 15. Themagnet recess 12A keeps the magnet from sliding along its surface planeand becoming detached while it is reciprocating. A sensor (magnetic orcontact, not shown) may also be implemented to illuminate an indicator75A (e.g., an LED, see FIGS. 2A and 17A) on the control box 1 to confirmthat the magnetic connection is securely made. This feature also alertsthe user if the connection becomes broken during use.

In an alternate embodiment, the magnet 33 (or 12) may only be located onone of the mating pieces, and a disc or cylinder of magnetic material,be located on the other.

It should be understood that this magnetic Luer lock coupling is by wayof example only. It is within the broadest scope of the invention toinclude other types of releasably securable connector mechanisms, suchas, but not limited to, threaded couplings.

As mentioned previously, the control box 1 includes a diaphragm 9 whichseals the control box 1 from contamination from the outside. As can beseen most clearly in FIGS. 2-2A, the diaphragm 9 permits magneticattachment of the clearing stem 26 so that the magnets 33/12 can makecontact while at the same time sealing the box 1 such that no debris,biological or other, enters the control box 1. FIG. 16A is an enlargedpartial view showing the sealing diaphragm 9 that does not interferewith motor shaft 15 motion. The diaphragm 9 prevents, among otherthings, the ingress of liquids into the control box 1. The diaphragm 9may also be located externally or on the boundary of the control box 1so that it can be cleaned more easily.

As also mentioned previously, the preferred control box 1 is that shownin FIG. 2B wherein a preferred novel clearing stem-control box interfaceis used. In particular, FIGS. 16B-16C depict the drive side of thecontrol box 1 which includes a sheath attachment bracket 83, analternate diaphragm 9A, a diaphragm sealing ring 84 (see also FIG. 2B),the motor (e.g., voice coil motor, VCM) shaft 15 along with an alternatemotor magnetic coupler 13A (e.g., a magnetic coupler for a VCM). As canbe seen from FIG. 16B, the alternate diaphragm 9A contains no holes orapertures through which the clearing stein 26 passes. The diaphragmsealing ring 84 secures the compliant alternate diaphragm 9A in place.To facilitate coupling the clearing stem 26 to this control box, as canbe seen most clearly in FIG. 16C, the proximal end of the clearing stem26 comprises an alternate clearing stem fitting 32A and an alternateclearing stem magnet 33A positioned within an alternate clearing stemmagnetic fitting 33B. In order to couple the clearing stem 26 to thecontrol box motor 14, the alternate clearing stein magnet fitting 33B isbrought into close proximity with the alternate diaphragm 9A such thatthe two magnets 12 and 33A are magnetically coupled and abutting throughthe alternate diaphragm 9A. Thus, there is no breach of the seal of thecontrol box 1 because the alternate diaphragm 9A remains closed.Simultaneously, the alternate clearing stem fitting 32A is secured inthe sheath attachment bracket 83. As a result, reciprocation of themotor shaft 15 can occur without passing through any aperture or openingin the alternate diaphragm 9A. FIGS. 1 and IA depict a drive-end view ofthe clearing stem 26 coupled to the control box 1.

As can be appreciated from FIG. 3A, the wire stop 27 limits the amountof travel of the wire 28 to the right (i.e., towards the motor 14)during operation. In an alternate embodiment, as shown in FIGS. 3C and3D, the wire stop 27 has been removed and instead an alternate wire stop27A is used closer to the proximal end of the clearing stem 26. Thisalternate wire stop 27A comprises a stretchable/pliant (e.g., silicon)tube whose ends are bonded to the alternate clearing stem fitting 32A onone side and to the alternate clearing stein magnet fitting 33B on itsother side. This alternate wire stop 27A supports the wire 28 thatpasses through it. During operation, the alternate wire stop 27Acompresses and expands accordingly without interfering with wire 28oscillation/travel. This alternate wire stop 27A is preferred because itis located externally of the artificial tube 39 and thereby avoidshaving a stop at the working end of the wire 28 that could interferewith operation. Thus, the alternate wire stop 27A serves to keep thewire 28 from sliding out of the sheath 30.

As shown in FIG. 3A, the wire tip 29 of the wire is rounded to allow thewire 28 to break up a clog 40 (FIG. 4), and to resist penetrating anorgan (e.g., stomach or other tissue/organ, etc.) should the wire tip 29ever make its way close to an organ. The wire protrusion 28A may also begiven added flexibility by design compared to that of the rest of thewire 28, to further reduce the risk of the clearing stem wire tip 29having enough force to penetrate an organ (e.g., the stomach) and/or toincrease displacement at the wire tip 29 and facilitate clearing of theclog 40. As mentioned previously, the length of the wire protrusion 28Abeyond the end of the sheath 28 and the roundness of the wire tip 29strongly impact the ease of insertion into an artificial tube. Ideally,the wire tip 29 radius is 0.5 to 2.0 times the overall wire 28 diameter.The stiffness of the sheath 30 comprises a balance between being stiffenough to prevent the operator from clamping down on the wire 28 andstopping wire 28 motion versus being flexible enough to enter anartificial (e.g., feeding) tube 39 and to navigate curves in the tubeinner lumen 41 of the artificial tube 39.

Another safety feature of the present invention TCI is that the forcegenerated at the end of the wire tip 29 is less than 5% of the forcegenerated at the motor 14 and therefore, this force reduction provides asafety feature of avoiding puncturing an organ accidentally but yetproviding sufficient force to break up the clog 40 and helping to clearthe walls of the tube.

As mentioned previously, a stem stiffener 31 (FIGS. 3-3A) is provided atthe proximal end of the clearing stem 26 which prevents the operatorfrom over-bending the clearing stein 26 and thereby stopping thereciprocation. The stem stiffener 31 may be constructed of the samematerial (of a larger diameter than the wire 28 or sheath 30), may beintegrated into the sheath 30 via custom extrusion, or may beconstructed of a different material, such as any polymer or metal.

To prevent the “over-insertion” of the clearing stem 26, a tubedepth-control collar 22 (FIGS. 3-3A and 9A-9C) is provided. The tubedepth-control collar 22 comprises a tube depth-control collar body 24which includes an internal spring 25. A tube depth-control collar pushbutton 23 is provided to lock or unlock the tube depth-control collar22. In particular, as shown most clearly in FIG. 9A, the depth controlcollar push button 23 has a central passageway of push button 23A andthe tube depth-control collar body 24 has a central passageway of collarbody 24A. A spring 25 acts to misalign these two passageways 23A/24A.Thus, to re-position the tube depth-control collar 22 along the lengthof the sheath 30 (not shown), the depth control collar push button 23 isdepressed which momentarily relieves any clamping force on the sheath 30and the tube depth-control collar 22 can then be moved. When theoperator wishes to lock the tube depth-control collar 22 in position,he/she releases the tube depth-control collar push button 23 whichresults in the sheath 30 being clamped between an upper portion ofcollar body 24B of the tube depth-control collar body 24 and a lowerportion 23B of the tube depth-control collar push button 23. The forceapplied by the depth-control collar to the sheath 30 needs to becompressive enough to hold the tube depth-control collar body 24 inplace against the sheath 30, but not to clamp the sheath 30 onto wire28. Sheath length markings 30A (FIG. 3B) and integer markings 30B (FIG.3B) are provided to facilitate positioning the tube depth-control collar22 along the length of the sheath 30 depending on the length of theartificial tube 39 being cleared. The markings 30A/integers 30B are inascending or descending order from the distal end 30C of the sheath 30to the proximal end 30D. Along with the stiffness of the sheath 30, thespring constant of the spring 25 comprises a balance between the forcenecessary to maintain the tube depth-control collar body 24 in place onthe sheath 30 while avoiding the tube depth-control collar body 24 fromclamping down on the wire 28 and stopping wire 28 motion.

It should be understood that it is within the broadest scope of thepresent invention to include fixed tube depth-control collars 22A, suchas that shown in FIGS. 3C, 3D and 9D. In particular, a plurality ofclearing stems 26 may be provided, each having a fixed tubedepth-control collar 22A fixed at a predetermined length (e.g., 35inches, 44 inches, etc.) along the sheath 30. FIG. 9D shows the fixedtube depth-control collar 22A abutting the proximal end of the feedingtube FT thereby preventing the sheath 30 from entering any furtherwithin the feeding tube FT. Using this embodiment, the operator selectsone clearing stem 26, from a plurality of clearing stems 26, having aparticular fixed tube depth-control collar 22A and clearing stem 26length that is appropriate for the particular feeding tube FT thatcontains a clog that is to be cleared.

To facilitate clearing, a brush may be included on the wire tip 29 or onthe distal end of the sheath 30. For example, FIG. 6 depicts a wire tipbrush 35 on the end of the wire 28 whereas FIGS. 7 and 8 depictrespective brushes with sheath tip brush 36 and forward swept sheath tipbrush 37 on the end of the sheath 30. Therefore, as the wire protrusion28A reciprocates, the wire tip brush 35 cleans the tube walls or whenthe sheath 30 is inserted into the artificial tube 39, the insertionmotion causes the brush 36 or 37 to clean the tube walls, as well asfacilitate the movement of the dislodged blockage and/or its pieces. Inparticular, the small brush (e.g., polyester, foam, or twisted in wire)on the distal end of sheath (36 or 37) or wire (35) provides morethorough clearing of tube walls. With particular regard to brush 36 or37, mounted on the distal end of the sheath 30, the brush 36 or 37 isnon-moving in this embodiment, which helps to clear excess particlesfrom tube walls after the wire protrusion 28A has cleared the clog 40and as the sheath 30 is retracted and moved out of the artificial tube39. The advantage of the brush 36 or 37 on the sheath 30 is that thebrush 36 or 37 does not impede the wire 28 motion at all. It should benoted that the forward swept sheath tip brush 37 on the distal end ofthe sheath 30 shown in FIG. 8 includes bristles that are swept in thedistal direction. This makes clearing effective as the forward sweptsheath tip brush 37 is inserted into the tube, but also allows for asmoother retraction because the sweep-direction of the bristles reducesthe resistance of the forward swept sheath tip brush 37 when theoperator is removing the clearing stem 26 from the artificial tube 39.This reduced resistance minimizes the chance of dislodging theartificial tube 39 from the patient when the clearing stem 26 isremoved.

Other configurations of the clearing stem 26 include a range of wire tip29 designs. For example, a sphere (e.g., metal or plastic) anywherealong the length of the wire protrusion 28A may be included, such as theball tip 34E in FIG. 5D. If the sphere is included at the wire tip 29,this helps prevent the inadvertent insertion into an organ (e.g.,stomach) wall, and also prevents the inadvertent retraction of the wireprotrusion 28A into the sheath 30 during use, setup or clearingillustrated in FIG. 5D. Another alternative end may comprise a plasticend wherein a plastic tip is fused or ultrasonically welded to the wiretip 29 and which may comprise the shape of a point, helix, or radius,etc., illustrated in FIG. 5 a. In addition, these alternative tips mayfurther comprise ridges or a pattern designed to sweep broken debrisaway from the clog 40 site. FIG. 5A depicts the distal end of the wire28 with a plastic wire tip 34. An alternative tip design may include aspring guide wire design possibly exemplified by Lake Region MedicalParagon Pre-coat guide wires. Another alternative tip could be flexiblesuch as a Tecoflex® tip which causes the tip to slide across contactedtissue rather than puncturing tissue, thus providing an additionalsafety feature.

FIG. 5B depicts another alternative end which may comprise a smallspring mechanism which provides increased displacement and protectionagainst an over-insertion puncture. In particular, a plastic or metalalternate tubing tip 34A is positioned over the distal end of the wire28. The rear end of the alternate tubing tip 34A is secured to one endof a tip compression spring TCS that is slid onto the wire 28. A fixedmember 34B is secured to the wire 28 and to the other end of the tipcompression spring TCS. Thus, the alternate tubing tip 34A acts as afurther protection against accidental contact with soft tissue, sincethe alternate tubing tip 34A can only be retracted when it encounters asolid object, e.g., a clog, and whereby the wire tip 29 is then exposedto the solid object. Once the clog is cleared, the alternate tubing tip34A springs back in position ahead of the wire tip 29 to shield it fromcontact with bodily tissue or organs. Moreover, the wire tip 29 may alsocomprise a small gripping mechanism wherein the wire tip 29 contains asmall cable-actuated gripping mechanism to dislodge clogs 40 or retrievesamples of clog material. In particular, FIG. 5C depictsgripping/chopping mechanism 34C that are hinged or pivoted at pivotpoint 34D. By actuating a control member (not shown, e.g., a cable, rod,electromechanical motor, piezoelectric motor etc.), thegripping/chopping mechanism 34C can be closed around a clog specimen orused to tear away the clog material to dislodge clogs or retrieve asample of the clog material.

An alternative design to the wire 28 is the provision of a flexibleportion of wire 28 located between the end of the sheath 30 and the wiretip 29. Thus, the wire protrusion 28A may comprise a material that ismore flexible than the remaining part of the wire 28 that couples to themotor shaft 15.

Control Box Motor for TCI

As mentioned previously, the motor 14 drives the wire 28, creatinglinear displacement. The back and forth displacement of the wire 28allows it to break up and clear clogs 40 in artificial tubes (e.g.,enteral feeding tubes and especially NG feeding tubes), whilesimultaneously cleaning debris from the tube walls. The wire tip 29 ofthe wire 28 has a linear displacement, preferably, in the range of 0.25to 25 mm, more preferably 2-10 mm from the distal end of the sheath 30.The frequency of operation of the motor shaft 15 preferably varies from10 to 100 Hz but more preferably in the 15-40 Hz range. The motor 14 hasa range of displacement preferably from 1-40 mm and more preferably inthe range of 10-30 mm. The motor blocking force (i.e., the maximum forceoutput) has a preferable range of 2-25N and more preferably 6-14N.

The reciprocating motion of the clearing stem 26 of the presentinvention TCI can be achieved using a variety of motor technologies,such as, but not limited to, voice coil motors (VCMs) as illustrated forthe motor 14 (FIGS. 2-2B, 10-10A and 15), DC motors 49 (FIG. 11,11A-11C), piezoelectric transducers, including amplified piezoelectricactuator motors 59 (APA, such as those disclosed in U.S. Pat. No.6,465,936 (Knowles, et. al), whose entire disclosure is incorporated byreference herein) (FIGS. 12-12A), piezoelectric actuators, activepolymer compound actuators, solenoid motors 55 (FIGS. 13-13A), pneumaticmotors 42 (FIGS. 14-14A), magnetorestrictive transducers,electrorestrictive transducers, etc.

As shown in FIGS. 2-2A, 10-10A, and 15 the motor 14 may comprise a voicecoil motor (VCM) having a VCM body 16 mounted within end bearings 18, adisplaceable motor shaft 15, dampers or spring 19, and magnets 20mounted to the motor shaft 15, with pole pieces 21 A, 21B and 21C (FIGS.2A, 10A and 15) located at the ends and within the center of the magnets20. Coil windings 17 are wound around the VCM body 16 and thus do notinterfere with VCM motor shaft 15 displacement. Motor mounts 7 and motormount dampers 8 secure the motor 14 within the control box 1 whileavoiding direct coupling against the bottom surface of the control box1. A motor printed circuit board (PCB) 11 distributes the currentcommands from the electronics 10 to the coil windings 17 through wires53. When an electric current is applied through the coil windings 17, amagnetic field, due to Ampere's Law, is produced inside the coilwindings. The non-uniform magnetic field at the ends exerts a force onthe permanent magnets 20. Alternating the current alternates thedirection of the magnetic field gradients and results in a reciprocatingmotion of the motor shaft 15 with respect to the VCM body 16. Themagnitude of the force is determined by the magnetic flux density, whichis proportional to the number of turns per length of the coil, currentmagnitude, cross-sectional area of the coil, as well as the strength ofthe permanent magnets 20. The springs 19 absorb the energy associatedwith abrupt changes in the direction of the inertial force of themagnets 20 and VCM body 16 when actuated, resulting in a lowering ofvibration and increasing the tube clearer TCI usability and efficiency.

By way of example only, the spring constant of the springs 19 can rangefrom 0.5-5 lb/in, and more preferably 1.5-2.5 lb/in.

A soft stop SS may be installed at the free end of the VCM motor shaft15 because the shaft tends to drift off center during use.

A further variation of the use of a plurality of magnets is to arrangethe plurality of magnets into two “driving members” disposed between thepole pieces 21A-21C, mentioned previously. Pole pieces 21A-21C aretypically ferromagnetic and are preferably stainless steel. As shownmost clearly in FIG. 15, the south poles of the first magnetic drivingmember 20N and the south poles of the second magnetic driving member 20Sare fixedly secured to the opposing faces of the pole piece 2 IB inorder to provide a zone of maximum magnetic flux density which extendsradially outwardly from the central portion of the pole piece 21B,similar to the configuration disclosed in U.S. Pat. No. 4,363,980(Peterson) whose entire disclosure is incorporated by reference herein.Alternatively, each magnetic driving member 20N and 20S may be replacedwith a single elongated permanent magnet, rather than using a pluralityof magnet elements as shown in FIG. 15. In either case, the drivingmembers 20N and 20S have opposite pole directions.

It is within the broadest scope of the present invention that therelative positions of the coil windings 17 and the magnets 20 arereversed (not shown), i.e., the coil windings 17 are wound directlyaround the motor shaft 15 and the magnets 20 are positioned around theVCM body 16 and thus do not interfere with the motor shaft's 15reciprocation.

Alternatively, a dual coil motor or actuator (also not shown) is alsowithin the broadest scope of the present invention. In particular,instead of using magnets 20, two coil windings are used wherein one coilis wound directly around the motor shaft 15 and a second or outer coilis wound around the first or inner coil but without interfering withshaft displacement. Each coil is supplied with respective alternatingcurrent sources which generate respective electromagnetic fields thatalso generate a reciprocating motion of the motor shaft 15. The innercoil may conduct direct current DC while the outer coil conductsalternating current AC. Alternatively, the inner coil may conductalternating current AC while the outer coil conducts direct current DC,or both the inner coil and the outer coil may conduct alternatingcurrent AC.

Moreover, to reduce vibration caused by the oscillating motion of themotor shaft 15, a secondary VCM or counter balance mechanism 14A ofsimilar size (also referred to as a “countermass” or “counterbalance”)may be included and driven at an opposite phase (e.g., 180° phase lag)for cancelling vibration caused by the motor 14. See FIG. 2B. Thus, whenthe tube clearer TCI is operated such that the first VCM is activated tocause the motor shaft 15 to move, a first momentum vector is produced.The second VCM is operated such that it creates a second momentum vectorequal in magnitude but opposite in direction to the first momentumvector, such that the net sum of the first and second momentum vectorsis minimized and preferably equal to zero. In particular, to maximizevibration reduction, the moving parts (shaft, magnets, pole pieces,attachments, etc.) of the counter balance mechanism 14A should have amoving mass and velocity (frequency and displacement) equal to that ofthe moving parts of the actuating motor 14. This is based on theprinciple of Conservation of Momentum. The sine waves that actuate bothVCMs must have a 180 degree phase lag between them. This causes theirforces to be opposite and (ideally) equal, cancelling each other out. Assuch, operation of the tube clearer TCI does not cause “chatter” andtherefore there is no irritation to the operator or patient.

DC Motor 49

The motor may also comprise DC or DC brushless motor 49 for creatingreciprocating displacement via a scotch yoke SY or similar mechanism.FIG. 11 depicts the control box 1 using a DC motor 49 and scotch yoke SYas the actuating mechanism. No signal generating electronics are neededfor this application since the DC motor 49 is simply turned on to causea rotating crank CR to drive the scotch yoke slider 50 and the scotchyoke shaft 52 in reciprocating motion. The adapter 51 transmits thescotch yoke SY motion to the scotch yoke shaft 52. FIGS. 11A-11C showthree still frames as an example of scotch yoke SY motion. FIG. 11A andFIG. 11B show Scotch yoke forward displacement direction 50A and FIG.11C shows Scotch yoke rearward displacement direction 50B are moving ina reciprocating motion.

APA Motor 59

An amplified piezoelectric actuator (APA) 60 creates reciprocatingdisplacement in the lower range, preferably (0.1 to 2.0 mm), anchored tothe control box 1. One or more APA motors 59 can be used in series, asthis increases displacement. FIGS. 12-12A depict the control box 1 withan APA as the actuating mechanism. In particular, the APA actuator 60 ismounted to the control box via an actuator mount 61 which is indirectlycoupled to the control box 1 bottom via motor mount damper 8. Anactuator shaft 62 conveys the reciprocating motion, from APA actuator 60expansion and contraction, to the clearing stem (not shown) via themagnetic coupling discussed earlier for the other embodiments.

Langevin Transducer 77

A Langevin transducer 77 can be used for the motor 14. As shown in FIG.12B, the Langevin transducer comprises a plurality of piezoelectricelements 78 are arranged to cause a horn 81 to vibrate to form thereciprocating motion. The horn 81 is secured to an actuator mount 61using a pre-stress bolt 79. The Langevin transducer 77 includes a tailmass 80 for bolt-clamping the Langevin transducer 77 to the actuatormount 61. The forward end of the horn 81 is tapered such that a distalend of the horn passes through the control box alternate diaphragm 9A. Aclearing stem attachment 82 is provided to receive/mate with theclearing stem 26 as discussed previously. A power source (not shown)that provides the proper activation energy is coupled through the powerplug 5 and via electronic control wires 53.

It should be noted that activation of the Langevin transducer 77 createsreciprocating motion with the introduction of several overtones (viz.,first-fourth overtones), shown in FIG. 12C. As part of the design of thepresent invention, the lateral displacement caused by these overtones iskept to a minimum. In particular, the piezoelectric elements 78 (e.g., aplurality of piezoelectric ceramic discs) are held in compressionbetween the tail mass 80 and horn 81; and the pre-stress bolt 79 passingfrom a proximal end of the tail mass 80 and threading into the horn 81.Vibratory motion is caused by the activation of the piezoelectricelements 78 upon being exposed to an alternating electric field such asfrom an AC electrical current applied to electrical contacts (not shown)formed on opposing sides of each of the piezoelectric elements 78. Thevibratory motion is translated as a standing harmonic wave spanninglongitudinally across the horn 81 and to the clearing stein (not shown).Therefore, when operated at ultrasonic frequencies, the Langevintransducer 77 translates the ultrasonic energy as a reciprocatingvibration to the clearing stem 26, and produces a standing wave withinthe flexible member. The horn 81 and tail mass 80 are made of a metalsuch as titanium, stainless steel or, preferably, aluminum. Thepre-stress bolt 79 is generally of stainless steel, but not limitedthereto.

Solenoid Motor 55

The solenoid motor 55 shown in FIGS. 13-13A mounted in the control box 1operates in a very similar manner as does the motor 14, discussedpreviously. A return spring 58 is required with the solenoid 56 since ithas one-way actuation. In particular, the electronics 10 are configuredto pulse the solenoid 56 such that during the pulse, the solenoid shaft57 is driven to the left in FIGS. 13-13A and when the pulse isterminated, the return spring 58 restores the solenoid shaft 57 to theright. This action is repeated at the frequencies discussed previously.

Pneumatic Motor 42

FIGS. 14-14A depict a pneumatic motor 42 for creating the reciprocatingmotion. In particular, the pneumatic motor shaft 44 is driven by thepneumatic motor 42 which receives pneumatic pulses from a pneumaticpulse generator (not shown) via an air supply inlet 54 on the controlbox 1 and through internal tubing 47. The pneumatic motor 42 ispositioned within a pneumatic motor housing 43 which includes apneumatic motor diaphragm 46 for distributing the pneumatic pulse evenlyto the pneumatic motor shaft 44, thereby maintaining its alignment,while at the same time providing a tightly-sealed motor configuration.The pneumatic pulse causes the pneumatic motor shaft 44 to be driven tothe left while compressing a return spring 58. Once the pneumatic pulseis terminated, the return spring 58 restores the pneumatic motor shaft44 to the right. This action is repeated at the frequencies discussedpreviously.

Electronics

FIG. 17A provides a block diagram of the electronic system 63 containedwithin the electronics 10. A microprocessor (e.g., MSP430F2618TPMR)controls the power electronics 73 to the motor 14. Although not shown, apower supply (e.g., an Autodyne UL medically-approved power supplyAMP6301-08) converts the 120 VAC from the wall outlet to 24 VDC. Amicroprocessor power unit MPU 69 (e.g., a voltage regulator circuit,such as the LM317/LM337) reduces the incoming (e.g., +24 VDC) power 67to a lower power (e.g., +3.3 VDC indicated by 70) for use by themicroprocessor 71. The microprocessor 71 controls the motor 14 via powerelectronics 73, as well as all of the associated indicators, such as LEDindicators 3, 4, 75 and 75A. The power electronics 73 convert themicroprocessor 71 commands into a power signal to motor 76 (24 Vp-p AC)using internal inverters to activate the motor 14. An enable switch 72is provided to permit the clearing stem to be continuously reciprocatedfor a predetermined period of time (e.g., 4-20 minutes), which avoidsrunning the device TCI for too long but provides sufficient time toeffect clearing the clog. A control box power switch 2 is coupled to themicroprocessor power unit (MPU) 69 via a fuse 66. A power indicator(e.g., LED) 3 is provided on the control box 1. When the control box 1is externally powered, e.g., from 120 VDC, 60 Hz wall power, apower-cord (not shown) is supplied with the control box 1, and whichincludes an AC/DC converter. It should be understood that this does notlimit the operation of the present invention to wall power in any mannerand that the control box 1 can be operated off any type of power source,including battery power.

The electronic system 63 may also include a displacement sensor DS(e.g., an LVDT (e.g., Macro Sensors CD 375-500) or force sensor/loadcell (e.g., Futek LPM 200); or eddy current sensor (e.g., Micro-Epsiloneddy NCDT 3010), etc.) for accomplishing closed loop motor control aswell as detecting changes in the clearing process. For example, thesensor DS forms a closed loop with microprocessor 71 for maintaining themotor shaft 15 in a centered position, which maintains the motor 14where the force is the greatest and provides optimum control.Alternatively, the sensor DS may comprise a displacement/force feedbacksensor or even an optical displacement sensor (e.g., VariohmEurosensor). The DS sensor output may also be used for self-centering ofthe wire 28 during operation. As part of the closed loop control, it maybe advantageous to also change any DC offset to alter the force profileat the wire tip 29 and to provide more power to one side.

In addition, an impedance sensor/current sensor IS may be included fordetecting the change in voltage/current of the motor 14 andcommunicating with the microprocessor 71 for determining the status ofthe clearing process, such as initial contact with blockage, passagetherethrough, etc. This status can be conveyed through a display orclearing status indicator 75 (e.g., LEDs, 7-segment displays, audibleindicators, etc.) or a series of differently-colored LEDs 75 (e.g., fromgreen to yellow to red). Alternatively, where the displacement sensor DScomprises a displacement/force feedback sensor, this sensor's output canbe used to detect when the clog 40 is contacted and when it ispenetrated.

As mentioned earlier, in order to indicate that the clearing stem magnet33 and the control box magnet 12 are coupled properly, amagnetic/conductive sensor to determine if a solid clearing stemconnection has been made which can then be provided to an indicator 75A.By way of example only, a magnetic sensor could be implemented todetermine safe connectivity between magnets in operation, such as aHoneywell Magnetometer, HMR2300. These magnetometers measure bothmagnetic field intensity and direction using their AnisotropicMagneto-Resistive sensors. The ability to acquire this information canbe utilized by the microprocessor 71 to ensure the magnet polarities arecorrect, and that the magnets field intensity is at a safe level (e.g.,they have not been de-magnetized). Similarly, an anti-tamper circuit mayalso be included in the electronic system 63 which interrupts operationif the control box 1 is attempted to be opened. A corresponding tampersensor may also be provided that causes the indicator 75A on the controlbox 1 to indicate if someone has opened, or attempted opening the lid ofthe control box 1. Furthermore, control box screws can be configured todisable operation of the control box 1, if they are attempted to beremoved during activation.

The microprocessor 71 can be programmed to drive the electronic system63 at the needed voltage and frequency, converting 120V 60 Hz wall powerto needed parameters to drive the motor 14 at, for example 15-40 Hz(e.g., 25 Hz). In particular, several fault conditions are programmedinto the microprocessor 71 for which it interrupts device TCI operation:

V_(input)<20VDC;

V_(input)>25VDC;

Overtemperature condition pertaining to the amplifier IC;Short circuit condition pertaining to the amplifier IC;Should any of these fault conditions occur, the microprocessor 71activates a fault indicator 4. Also, as discussed earlier, the enableswitch 72 permits the operator to initiate the reciprocating motionwithout the need to hold any trigger. The enable switch 72 permits thecontrol box 1 to maintain the reciprocating motion for a predeterminedperiod of time (e.g., 4-20 minutes) before the reciprocating motion isterminated.

FIG. 17B provides a flow diagram of the microprocessor 71 operation: atstep power up 85, the microprocessor 71 is powered up followingactivation of the power switch 2 by the operator. The microprocessor 71then conducts a one second step initialization 86. Once theinitialization 86 is completed the microprocessor 71 activates the powerindicator 3 (e.g., typically a green light (GL) or indication). At thispoint, device TCI remains in a disabled state until the enable switch 72is activated by the operator; “enable button pressed” step 89 of theflow diagram represents activation of the enable switch 72 resulting inthe enabled state 88 of the device where the clearing stein 26 is beingreciprocated as described previously. The microprocessor 71 thenmaintains operation of this reciprocation for the predetermined period(e.g., 4-20 minutes) shown as time interval 93 in the flow diagram. Atthe end of the predetermined period, the microprocessor 71 terminatesthe reciprocating movement of the clearing stein 26 and returns to stepdisabled 87. In addition, upon activation of the enable switch 72 by theoperator, the microprocessor 71 monitors the device TCI for the faultsdescribed above, indicated by the paths—fault detected 90 of the flowdiagram. If a fault 91 is detected by the microprocessor 71, themicroprocessor 71 terminates clearing stem reciprocation and activatesthe fault indicator 4 (e.g., typically a yellow light (YL) orindication). The microprocessor 71 then shuts down (step power cycle 92)the device TCI.

Operation of the present invention tube clearer TCI is as follows: ifwall power is being used, the connector end of the power cord (notshown) is inserted into power plug 5 (FIGS. 2-2A) on the control box 1and the other end of the power cord is coupled to a power supply whichis coupled to a standard 120V RMS/60 Hz three-prong outlet. The controlbox 1 is turned on using the power switch 2 which turns on the powerindicator 3 which verifies that the control box 1 is operating properly.

A new clearing stem 26 is removed from its packaging (but not discardedsince the contaminated clearing stem 26 will be placed in the packagingand then discarded). If a plurality of clearing stems 26 are providedwith tube depth-control collars fixed at different positions, theoperator needs to select the clearing stem which has the appropriatefixed collar position; if, the tube depth-control collar is adjustable,the operator needs to position the collar appropriately along theclearing stem.

The following discussion of the operation is based upon the control boxshown in FIGS. 2-2A, it being understood that this is by way of exampleonly. The wire end of the wire 28 comprising the clearing stem magnet 33is gently pulled out from within the sheath 30 and then the clearingstem magnet 33 is inserted into the bore of the Luer clearing stemconnector 6 until the operator feels the pull of the clearing stemmagnet 33 to the other magnet 12 and/or hears the magnets connect. Thesheath 30 is then pushed until the Luer clearing stein fitting 32 isflush with the Luer clearing stem connector 6 on the control box 1. TheLuer clearing stem fitting 32 is then twisted onto the Luer clearingstem connector 6. Next, the distal end wire tip 29 of the clearingmember 26 is inserted a few inches into the artificial tube. The enableswitch 72 is pressed to activate the reciprocating motion. While holdingthe artificial tube 39 in one hand, the clearing stem 26 is held in theother hand while the clearing stein 26 is advanced into the artificialtube. When the clog is initially encountered, the clearing statusindicator 75 changes to alert to the initial contact, and the operatorbegins to apply a slight force to the clearing stein 26. Facilitatingclog clearance can be achieved by the operator moving the clearing stein26 back and forth slightly to clear the clog. These steps are repeateduntil the clog has cleared, in which case, the clearing status indicator75 showing that the clog has been cleared activates. If the clog iscleared before the predetermined period (e.g., 4-20 minutes) is reached,the operator can depress the enable switch 72 again to stop thereciprocating movement and then depress the power switch 2 to shut offpower to the device TCI. The clearing stem 26 can then be removed fromthe artificial tube (e.g., feeding tube FT) and then the working end ofthe clearing stein 26 can be inserted into the packaging. The artificialtube should be flushed with water to verify that the clog has beencleared; if not, the working end of the clearing stem 26 should beremoved from the packaging and the clearing procedure repeated. If theclog is verified as being cleared, the clearing stem 26 is disengagedfrom the control box 1 in accordance with the version of the control box1 being used. For example, if the preferred control box 1 (e.g., FIG.16C) is being used, the alternate clearing stem fitting 32A isdisengaged from the sheath attachment bracket 83 and the alternateclearing stem magnet 33A is pulled away from the alternate diaphragm 9A;alternatively, where the Luer fitting version of the control box 1(e.g., FIG. 16A) is used, the operator twists the Luer clearing stemfitting 32 and removes the clearing stem magnet 33 end of the clearingstem 26 from the control box 1. In either situation, the clearing stem26 is placed back in the packaging and this is discarded in a suitablebiohazard container.

FIG. 29 provides a partial isometric end view of a working end 401 ofthe wire 28 of the clearing stem 26 which utilizes a sheath withchannels 30E that includes ports 402 which can be used for irrigationand/or aspiration. These ports 402 form the end of conduits in thesheath with channels 30E whose other ends are coupled to an aspirationsource (not shown, e.g., a vacuum source, etc.) and/or an irrigationsource (also not shown, e.g., a saline solution source, or other liquidsource). During clog break-up, broken pieces of the clog can beaspirated out of the artificial tube using the sheath with channels 30Eand where irrigating the clog vicinity is required, the sheath withchannels 30E can be used to deliver such liquids. When aspirating andirrigating simultaneously, aspiration flow should equal irrigation flowrate. The appropriate flow rates are preferably 1-15 in L/min.

Another alternate clearing stein configuration is replacing the wire 28with a hollow lumen or wire 403 to allow aspiration or irrigation downthe hollow lumen or wire 403 to achieve the same purposes discussed withregard to FIG. 29. This alternative configuration is shown in FIG. 29B.Thus, the sheath ports 402 and the hollow lumen or wire 403 maycooperate in different configurations to achieve irrigation/aspirationalternatively or simultaneously. By way of example, the sheath ports 402can be irrigating while the hollow lumen or wire 403 is suctioning, orvice versa. Alternatively, all of the ports 402 and the hollow lumen orwire 403 can be operating as irrigators or aspiration.

Another alternate clearing stem configuration is to use the indwellingartificial tube 39 effectively as the sheath, as illustrated in FIG.29C. In this case, a wire 28 or hollow lumen or wire 403 is inserteddirectly into an artificial tube 39 without the sheath 30. The motor 14drives the wire 28 or hollow lumen or wire 403 with motion as describedpreviously, to disrupt the clog 40. Although not shown, the tubedepth-control collar 22 may also be secured at the desired length toprevent over-insertion of the wire 28 or hollow lumen or wire 403, withthe collar 22 impacting the end of open proximal end of the artificialtube 39 during operation. Alternatively, the wire 28 or hollow lumen orwire 403 may include the fixed tube depth-control collar 22A to alsolimit over-insertion. Using this configuration, the hollow lumen or wire403 can achieve irrigation or suction alternatively. An advantage ofthis configuration is that elimination of the sheath can allow access tonarrower lumens. The phrase “completely exposed” when used with thedevice TCI means a device TCI that does not use a sheath.

Another alternate clearing stem configuration is a very narrow hollowlumen or wire 403 compared to the sheath 30 such that the arealdifferential between the hollow lumen or wire 403 and sheath 30 allowsfor aspiration/irrigation as illustrated in FIG. 29D.

Another alternate clearing stem configuration is the sheath 30 has twoports. One is quite small and is possibly used for a very narrow hollowlumen or wire 403 and the port 402 is used for aspiration/irrigation asillustrated in FIG. 29E.

Rotating Tube Clearer TC2

As with TCI, tube clearer TC2 is a mechanical tube clearer but insteadof generating reciprocating motion, tube clearer TC2 generates rotatingmotion to achieve artificial tube clearing, preferably for PEG feedingtubes. FIG. 18A depicts the tube clearer TC2 which comprises a reusablehandset 115 (which remains outside the artificial tube and the patient)having a motor 108 (e.g., a DC motor) that drives (rotates) a disposableor limited-reuse clearing member 114. The handset 115 is held by theoperator's hand 136 during the clearing procedure.

It should be noted that, alternatively, clearing member 114 may also behollow for irrigation or aspiration, or other features.

The tube clearer TC2 (FIG. 19) comprises a clearing member 114 thatincludes a magnetic connector 103 at one end which attaches to a torquelimiter 105 of the handset 115. Attached at the distal end of theclearing member 114 is a narrow flexible rod, preferably a polymer pieceof tubing with a clearing brush 101 located on its distal end. Theclearing member 114 can be solid or hollow. In the solid embodiment, thedistal end of the clearing member 114 is attached to the clearing brush101 and the proximal end of the clearing member 114 is attached to amagnetic connector 103. In the hollow embodiment, the wire holding theclearing brush 101 may extend the central length of the clearing member114 to the magnetic connector 103. The clearing member 114 is flexiblein order to conform to various radius of curvatures R. It is rotated bythe motor 108 within the handset 115. The rotary motion of the clearingbrush 101 clears the clog, occlusion, or debris from the tube (notshown).

Clearing Member and Connectors

The clearing member 114 comprises a polymer tube with a clearing brush101 inset at its distal end. The preferred polymer materials are nylonand polyurethane, although other materials may be used, such aspolytetrafluoroethylene (PTFE), Polyvinyl chloride (PVC), polyethylene,polypropylene, and fluoropolymer. The length of the clearing member 114is equal to the length of the feeding tube+/−one inch, depending onapplication. FIG. 22 shows the layout of the clearing member 114. At theproximal end of the clearing member 114 is a polymer magnetic connector103 which includes a clearing member magnet adapter 104 in its innerbore and which sits flush to the proximal end of the clearing member114. To attach the clearing member 114 to the handset, as shown in FIG.19, the magnetic connector 103 is inserted into a receiving bore 105Awithin the torque limiter 105 of the handset 115. Disposed within thebore end is a magnetic element 105B and wherein when the magneticconnector 103 is inserted into the receiving bore 105A, the clearingmember magnet adapter 104 and magnetic element 105B contact. Tofacilitate a tight connection, the magnetic connector 103 comprises ahexagonal-shape, or other non-round shape, that fits into acorrespondingly-shaped receiving bore 105A. DC motor 108 output isconveyed to the clearing member stem 102 through a gear train 107 andgear train output shaft 106.

The clearing brush 101 at the distal end has several unique features. Itcould be a twisted-in-wire type clearing brush 101 with a negative taperNT, as shown in FIG. 23. By way of example only, the clearing brush 101may comprise a twisted-in wire type; alternatively, the brush 101 maycomprise a helical-wound wire or other type brush design. “Negativetaper” implies that the dealing brush 101 bristles are wider in diameterat the distal end than at the proximal end of the clearing brush 101.There are several reasons for this configuration in the clearingmember's 114 design. Most conventional brushes have a taper smaller atthe distal end and larger at the proximal end. However, for thisapplication it would require over-insertion to clear the full bore ofthe end of the artificial tube (e.g., feeding tube) 119. The negativetaper NT also allows the helix-type wound clearing brush 101 to beextended rearward, as shown by the path of freed clog particles arrow120 in FIG. 23. When rotating (indicated by the rotation of brush arrow121), this clearing brush 101 design forces wicking of the loosened clogdebris away from the clog 122 also in the direction of the path of freedclog particles arrow 120. This is important for fast, effectiveclearing. If the clog 122 was not removed from the clog site, it couldbe compacted further, making the clog 122 even more difficult to remove.The negative taper NT also allows for contact with the tube walls (inorder to clean them), but only in a limited area. Having contact only ina limited area reduces the amount of drag on the artificial tube 119 andthe torque transmitted to it and thus this minimizes any chance ofdislodging the artificial tube 119 from within the patient when theclearing member 114 is removed from the artificial tube 119. The shapeof the (distal) tip of the clearing brush 101 is also important for thisapplication. Unlike many standard twisted-in-wire brushes, which are cutat the ends after twisting, the TC2 clearing brush 101 could possibly bewound with a rounded tip—the wire bends 180 degrees. This bend preventsany sharp end from coming into contact with the stomach, intestine, orother organs/tissues if over-inserted past the end of the artificialtube 119. Thus, the clearing brush 101 transfers minimal torque due toits unique geometry, but its helical design is also able to removeloosened debris from the clog 122.

In another embodiment, the brush tip 101A (FIG. 19) radius of theclearing brush 101 can be modified, e.g., rounded to allow the clearingbrush 101 to break up a clog, but to not penetrate an organ (e.g.,stomach or other tissue/organ, etc.) should the brush tip 101A ever makeits way close to an organ. The clearing brush 101 may also be retractedfrom the distal end of the clearing member to decrease the chance of theclearing brush 101 catching in stomach or other tissue. In anotherembodiment, the brush tip 101A can be modified by the addition of aflexible tip such as a Tecoflex® tip. In another embodiment, brush tip101A can be modified by the addition of ball tip 34E as illustrated inFIG. 5D.

Handset 115

Preferably, the handset 115 is shaped like a pistol, with contours tofit the user's fingers comfortably while he/she is using it, as shown bythe operator's hand 136 (FIG. 18A). An index finger trigger 109 controlsoperation. The trigger 109 is a momentary power switch that onlyprovides power when being pressed. The handset 115 is composed of threeparts, one battery cover and two halves which are fastened together byscrews or built-in snap fit connectors to form a handset housing 113. Italso contains an isolated battery compartment 112 to facilitate battery111 changes without exposing any components to contaminants that couldcause device failure or reduce reliability. A control circuit 110 (FIG.19) conveys power to the DC motor 108.

In this embodiment the handset contains an isolated compartment in whicha common battery size is used. For example, the handset 115 can bedesigned to accommodate any battery size such as 9V, AA, AAA, or aspecialty size and a plurality of batteries where required.Alternatively, the handset 115 may comprise a rechargeable battery suchthat there is no need to remove any batteries. A charger (not shown) mayaccompany the handset 115 such that the rechargeable battery can beinductively charged and this configuration has advantages over thebattery operated setup, including: no panels are removable on thehandset 115 which eliminates the possibility of contamination; and alsoreduces cost and disposal of batteries. The inductive charger maycomprise a base unit, rechargeable battery, and circuitry. The base unitmay comprise an enclosure with a slot or depression or cradle into whichthe handset 115 is positioned. The base unit plugs into a standard 120Voutlet. A coil in the base unit transmits a magnetic field to a coil inthe handset 115, and a charging circuit would transform the signal tothe correct voltage and route it to the rechargeable battery located inthe handset 115.

Motor

The motor 108 of the tube clearer TC2 is preferably a DC motor or abrushless DC motor and gear combination. The gear mechanism may be aprecision gear head, such as one utilizing a planetary gear train 116 ora compound gear train 118 utilizing two or more standalone gears. Motorand gear output speed ranges from 600 RPM to 1800 RPM, more preferably740 to 1140 RPM. The torque limiter 105 is also preferred in thisembodiment. The maximum output torque can preferably range from 20 mNmto 40 mNm with a more preferable torque of 24 to 34 mNm. A voltage ofless than or equal to 9 volts DC is preferred to drive the motor 108,such that standard commercially-available batteries can be used. FIG. 20shows a DC motor 108 with a planetary gear train 116 whereas FIG. 21shows a DC motor 108 with a compound gear train 118 configuration thatis coupled to the motor output shaft 117. Thus, torque, speed andgeometry of the clearing stem define the optimal operation of the deviceTC2. Alternatively, the motor 118 itself may have a torque output ofpreferably 20 mNm to 40 mNm, with a more preferable torque of 24 to 34mNm, in which case the torque limiter 105 would not be necessary.

In another embodiment, a DC or brushless DC motor 108 and gearcombination is used in combination with a torque limiter 105. The torquelimiter 105 is attached in-line with the motor output shaft 117 andallows slippage once the maximum output torque is reached. In anotherembodiment, a DC or brushless DC motor 108 and gear combination is usedin combination with a hammering device, similar to that found in hammerdrills (U.S. Pat. No. 5,653,294 (Thurler, et al.) and whose entiredisclosure is incorporated by reference herein). This device creates anoscillatory motion along with the rotary motion to clear the clog. Inanother embodiment, the DC or brushless DC motor in all examples aboveis replaced with a piezoelectric motor with similar specifications.

Tube Depth-Control Collar

As with TCI, tube clearer TC2 comprises a tube depth-control collar 133,as shown in FIG. 24. This depth-control collar permits one-handedoperation using no special tools. The tube depth-control collar 133mounts along the rod portion of the clearing member 114. The tubedepth-control collar 133 is formed to be well-balanced and lightweightso as to not cause unwanted harmonics in the clearing member 114 duringrotation. The tube depth-control collar 133 comprises a lightweight,circular tube depth-control collar housing 129 which includes adisplaceable tube depth-control collar push button 130 that acts againsta preloaded spring 132 bias and which locks against the clearing member114 which passes through the opening for clearing member 131. FIG. 18Adepicts the tube depth-control collar 133 on the clearing member 114.

Motor Torque Limiting

In a preferred embodiment of the handset 115, the torque applied to theclearing member 114 is limited by controlling the voltage and currentapplied to the DC motor and ultimately to the gears. These voltage andcurrent limits are established by testing and determining the minimumangle of twist that are unacceptable when the clearing brush 101 is in alocked condition within tubes under test. An alternative method involvesthe use of a DC motor with a torque limiter 105 as depicted in FIGS. 19and 25. The torque limiter 105 is a two-piece patterned disc, preloadedby a preload spring 125. The spring force controls torque at which discslippage occurs. In particular, the torque limiter 105 comprises aninput coupler 123, a torque limiter output shaft 135, a preload collar134 and a torque limiter profile 124. The input coupler 123 couples tothe gear train 107 and the torque limiter output shaft 135 couples theclearing member 114. As can be appreciated, when a certain appliedtorque is exceeded, the torque limiter 105 is designed to slip at theinterface or torque limiter profile 124 to disengage and thereby preventthe clearing member 114 from exceeding the torque limit.

Clearing Member Control

The tube clearer TC2 must control harmonics so that the clearing member114 does not become uncontrollable and cause injury/damage. Duringdevice activation, the tube clearer TC2 rotates the clearing member 114with a displacement diameter that is preferably from 0 mm to 40 mm and amore preferred diameter of 254 mm or less. FIG. 26 shows multi-nodalharmonics (i.e., node points 126) occurring in the clearing member 114while spinning and also depicts the maximum desired displacement 127A.This is preferred as its shape limits the displacement by geometry. Thedistance between the first two nodal points 126 is indicated by distancebetween nodal points 128, and as can be seen in FIG. 26, this distancedecreases for subsequent nodal points 126. The maximum desireddisplacement 127A of the clearing stem is preferred to be kept to 25.4mm or less. In contrast, FIG. 27 depicts a commercially-available rotarytool 115A (e.g., a hand-held drill) rotating the clearing member 114,showing the undesirable profile of rotating stem 129A (and itsundesirable corresponding maximum radial displacement 127B) of theclearing stem motion because there is only one nodal point at theproximal end of the clearing member 114. This type of deformation is notpreferred because it is more likely to be unstable.

FIG. 28 depicts a block diagram of the electronics of the device TC2. Inparticular, a DC motor 108 provides the rotational motion to theclearing stem 114. The motor 108 receives its input voltage 140 from avoltage regulator 137 which in turn receives power 139 from a powersource or battery 111 (e.g., 9V battery, a rechargeable battery, etc.)when the trigger 109 is activated by the operator. A power indicator 138(see FIG. 18A also), driven by the voltage regulator, is also provided.

FIG. 29A provides a partial isometric end view of the device TC2 showingthe clearing brush 101 coupled to the clearing member stem 102 whichutilizes a sheath with channels 30E that includes ports 402 which can beused for irrigation and/or aspiration. These ports 402 form the end ofconduits in the sheath with channels 30E whose other ends are coupled toan aspiration source (not shown, e.g., a vacuum source, etc.) and/or anirrigation source (also not shown, e.g., a saline solution source, orother liquid source). During clog break-up, broken pieces of the clogcan be aspirated out of the artificial tube using the sheath withchannels 30E and where irrigating the clog vicinity is required, thesheath with channels 30E can be used to deliver such liquids. Whenaspirating and irrigating simultaneously, aspiration flow should equalirrigation flow rate. The appropriate flow rates are preferably between1-15 in L/min. The clearing brush 101 can also be placed back along theclearing member stem 102 away from the distal end of the clearing member114 to decrease the potential for the clearing brush 101 grabbing orinteracting with the stomach or other organ or tissue. Alternatively,the various configurations shown in FIGS. 29 and 29B-29E can also beused with the device TC2. The phrase “completely exposed” when used withthe device TC2 means a device TC2 that does not use a sheath.

FIGS. 18B-18C depict an alternative voice coil motor tube clear deviceTC2. Instead of using a “pistol-style” housing, the device TC2 of FIGS.18B-18C comprise an elongated hand grip 301. In addition, unlike therotational motion of the TC2 device shown in FIG. 18A, the alternativevoice coil motor tube clear device 300 generates reciprocating motion(as discussed previously with regard to the TCI devices). In particular,within the hand grip 301 is positioned a voice coil motor 305 that, whenenergized, causes the clearing stein 303 to reciprocate. The tip of theclearing stem 303 includes a clearing brush 304. As shown most clearlyin FIG. 18B, a clearing stem adapter 302 is provided on an end of thehand grip 301 for securing the clearing stem 303 to the voice coil motor305 in the hand grip 301. A power indicator 138 is also provided toindicate when power is being provided to the clearing stem 303 forreciprocating motion. A power switch/trigger 109A is provided so thatthe user can manually control the activation of the device, similar tothe pistol-style embodiment.

It should be noted that, alternatively, clearing stem 303 may also behollow for irrigation or aspiration, or other features and may havesimilar configurations as shown in FIGS. 29-29E.

It should be further understood that the preferred embodiments of thepresent invention are for the in-situ clearing of artificial lumens in aliving being, but that these embodiments can be used for clearing lumenslocated outside of the living being, as well as for clearing other typesof lumens not associated with living beings.

Now that exemplary embodiments of the present invention have been shownand described in detail, various modifications and improvements thereonwill become readily apparent to those skilled in the art. Accordingly,the spirit and scope of the present invention is to be construed broadlyand limited only by the appended claims, and not by the foregoingspecification.

APPENDIX Reference Characters and their Associations

APA Amplified Piezoelectric Actuator TCI CR Crank TCI DS DisplacementSensor TCI IS Impedance Sensor TCI NT Negative Taper Angle TC2 SY ScotchYoke TCI SS Soft Stop TC1/TC2 TCI Tube Clearing Device 1 TCI TC2 TubeClearing Device 2 TC2 TCS Tip Compression Spring TCI GL Green Light TCIYL Yellow Light TCI FT Artificial/Feeding Tube TC1/TC2 R Radius ofCurvature TCI  1 Control Box TCI  2 Power Switch TCI  3 Power IndicatorTCI  4 Fault Indicator TCI  5 Power Plug TCI  6 Clearing Stem ConnectorTCI  7 Motor Mount TCI  8 Motor Mount Damper TCI  9 Diaphragm TCI  9AAlternate Diaphragm TCI  10 Electronics TCI  11 Motor PCB TCI  12 MagnetTCI  12A Magnet Recess TCI  13 Motor Magnetic Coupler TCI  13A AlternateMotor Magnetic Coupler TCI  14 Motor TCI  14A Counter Balance MechanismTCI  15 Motor Shaft TCI  16 VCM Body TCI  17 Winding TCI  18 End BearingTCI  19 Spring TCI  20 Magnets TCI 20N-20S Magnetic Driving members TCI21A-21C Pole Pieces TCI  22 Tube Depth-Control collar TCI  22A FixedTube Depth-Control collar TCI  23 Depth Control Collar Push Button TCI 23A Central passageway of push button TCI  23B Lower portion of pressbutton TCI  24 Tube Depth-Control Collar Body TCI  24A Centralpassageway of collar body TCI  24B Upper portion of collar body TCI  25Spring TCI  26 Clearing Stem TCI  27 Wire Stop TCI  27A Alternate WireStop TCI  28 Wire TCI  28A Wire Protrusion TCI  29 Wire Tip TCI  30Sheath TCI  30A Sheath length markings TCI  30B Integer markings TCI 30C Distal End TCI  30D Proximal End TCI  30E Sheath with Channels TCI 31 Stem Stiffener TCI  32 Clearing Stem Fitting TCI  32A AlternateClearing Stem Fitting TCI  33 Clearing Stem Magnet TCI  33A AlternateClearing Stem Magnet TCI  33B Alternate Clearing Stem Magnet Fitting TCI 34 Plastic Wire Tip TCI  34A Alternate Tubing Tip TC1/TC2  34B FixedMember TC1/TC2  34C Gripping/Chopping Mechanism TCI  34D Pivot Point TCI 34E Ball Tip TC1/TC2  35 Wire Tip Brush TCI  36 Sheath Tip Brush TCI 37 Forward Swept Sheath Tip Brush TCI  38 Nursing Cart TCI  38A PoleTCI  39 Artificial Tube TCI  40 Clog TCI  41 Tube Inner Lumen TCI  42Pneumatic Motor TCI  43 Pneumatic Motor Housing TCI  44 Pneumatic MotorShaft TCI  46 Pneumatic Motor Diaphragm TCI  47 Internal Tubing TCI  48Scotch Yoke Motor TCI  49 DC Motor TCI  50 Scotch Yoke Slider TCI  50AScotch Yoke Forward Displacement TCI direction  50B Scotch Yoke RearwardDisplacement TCI direction  51 Adapter TCI  52 Scotch Yoke Shaft TCI  53Wires TCI  54 Air Supply Inlet TCI  55 Solenoid Motor TCI  56 SolenoidTCI  57 Solenoid Shaft TCI  58 Return Spring TCI  59 APA Motor TCI  60Actuator TCI  61 Actuator Mount TCI  62 Actuator Shaft TCI  63Electronic System TCI  66 Fuse TCI  67 Power TCI  69 Micro ProcessorPower Unit (MPU) TCI  70 +3.3 VDC TCI  71 Microprocessor TCI  72 EnableSwitch TCI  73 Power Electronics TCI  75 Clearing Status Indicator TCI 75A Indicator TCI  76 power signal to motor TCI  77 Langevin Transducermotor TCI  78 Piezoelectric elements TCI  79 Pre-stress bolt TCI  80Tail Mass TCI  81 Horn TCI  82 Clearing Stem Attachment TCI  83 SheathAttachment Bracket TCI  84 Diaphragm Sealing Ring TCI  85 Power Up TCI 86 Initialization TCI  87 Disabled TCI  88 Enabled TCI  89 EnableButton Pressed TCI  90 Fault Detected TCI  91 Fault TCI  92 Power CycleTCI  93 Time Interval TCI 101 Clearing Brush TC2 101A Brush tip TC2 102Clearing Member Stem TC2 103 Magnetic Connector TC2 104 Magnetic AdapterTC2 105 Torque Limiter TC2 105 A Receiving Bore TC2 105B MagneticElement TC2 106 Gear Train Output Shaft TC2 107 Gear Train TC2 108 MotorTC2 109 Trigger TC2 109A Power Switch/trigger TC2 110 Control CircuitTC2 111 Battery TC2 112 Battery Compartment TC2 113 Handset Housing TC2114 Clearing Member TC2 115 Handset TC2 115A Commercial Available RotaryTool TC2 116 Planetary Gear Train TC2 117 Motor Output Shaft TC2 118Compound Gear Train TC2 119 Artificial Tube TC2 120 Path of Freed ClogParticles TC2 121 Rotation of Brush Arrow TC2 122 Clog TC2 123 InputCoupler TC2 124 Torque Limiter Profile TC2 125 Preload Springs TC2 126Nodal Points TC2 127 A Maximum Desired Displacement TC2 127B UndesirableDisplacement TC2 128 Distance between nodal points TC2 129 Tubedepth-control collar housing TC2 129 A Undesired Profile of RotatingStem TC2 130 Tube Depth-Control Collar Push Button TC2 131 Opening forClearing Member TC2 132 Preloaded Spring TC2 133 Tube depth-controlcollar TC2 134 Preload Collar TC2 135 Torque Limiter Output Shaft TC2136 Operator's Hand TC2 137 Voltage Regulator TC2 138 Power IndicatorTC2 139 Power TC2 140 Input Voltage TC2 300 Voice Coil Motor (VCM) TubeClear TC2 301 Hand Grip TC2 302 Clearing Stem Adapter TC2 303 ClearingStem TC2 304 Clearing Brush TC2 305 Voice Coil Motor TC2 401 Working EndTCI/TC2 402 Port TCI/TC2 403 Hollow Lumen or Wire TCI/TC2

While the invention has been described in detail and with reference tospecific examples thereof, it will be apparent to one skilled in the artthat various changes and modifications can be made therein withoutdeparting from the spirit and scope thereof.

1-63. (canceled)
 64. A method for the in situ clearing of blockages inartificial tubes completely or partially disposed within a living being,said method comprising: coupling a first end of a releasably-securableflexible clearing member to a controller and wherein said controllerremains outside of the living being, wherein the flexible clearingmember has a wire; inserting a second working end of said flexibleclearing member into an opening in the artificial tube; energizing saidcontroller such that said flexible clearing member experiencesrepetitive motion and positioning said flexible clearing member suchthat said second working end of said flexible clearing member comes intorepetitive contact with the blockage for clearing the blockage therein;and wherein said flexible clearing member clears the blockage whenpositioned within a straight portion or within a curved portion of theartificial tube; limiting the amount of insertion of the flexibleclearing member within the artificial tube while at the same timeallowing the wire to have repetitive motion within the artificial tube.65. The method of claim 64 wherein the step of limiting the amount ofinsertion involves restricting the amount of the flexible clearingmember that is inserted within the artificial tube using a tubedepth-control collar with said flexible clearing member that interfereswith the opening of the artificial tube, thereby preventing any furtherdisplacement of the flexible clearing member within the artificial tube.66. The method of claim 65 wherein said step of restricting the amountof the flexible clearing that is inserted comprises adjusting theposition of said tube depth-control collar along a length of saidflexible clearing member.
 67. The method of claim 64 wherein saidrepetitive motion comprises reciprocating motion that occurs along alongitudinal axis of the artificial tube.
 68. The method of claim 67wherein said step of inserting a second working end of said flexibleclearing member into an opening in the artificial tube comprisesinserting a second working end that includes a wire that is movablewithin a stationary sheath and wherein a first wire end is coupled to acontroller actuator that generates said reciprocating motion.
 69. Themethod of claim 68 wherein said step of inserting a second working endcomprises providing a tip compression spring that is coupled to a firstend of a tip tubing having a second end that is open to permit anextreme tip end of said wire to extend out of, or be retracted within,said tip tubing.
 70. The method of claim 68 wherein said step ofinserting a second working end comprises providing a gripper that formsan extreme end of said tip of said wire for gripping the blockage orportions thereof.
 71. The method of claim 68 wherein said step ofinserting a second working end comprises providing a brush at an extremetip end of said wire.
 72. The method of claim 68 wherein said step ofinserting a second working end tip comprises providing an extreme tipend of said wire in the form of a sphere.
 73. The method of claim 68wherein said step of inserting a second working end comprises providinga first sheath end having ports that permit irrigation or aspiration atsaid second working end through said ports when said ports are coupledto irrigation/aspiration sources.
 74. The method of claim 68 whereinsaid wire is hollow and wherein said step of inserting a second workingend comprises providing a first sheath end having ports having said wireproviding irrigation or aspiration therethrough.
 75. The method of claim68 wherein said step of inserting a second working end of said flexibleclearing member into an opening in the artificial tube comprisesinserting a second working end that includes a wire wherein the wire iscompletely exposed and wherein a first wire end is coupled to acontroller actuator that generates said reciprocating motion.
 76. Themethod of claim 68 wherein said step of energizing said controllercomprises reciprocating said clearing member in the range ofapproximately 15-40 Hz.
 77. The method of claim 76 wherein said step ofreciprocating said clearing member comprises displacing a tip of saidmovable wire in the range of approximately 2-10 mm.
 78. The method ofclaim 64 further comprising the step of providing a clearing statusindicator to an operator of said controller and said clearing member bydetecting changes in power input to said actuator.
 79. The method ofclaim 64 further comprising the step of providing a tamper indicator toan operator of said controller pertaining to any tampering of saidcontroller or if said clearing member is not properly connected to saidactuator shaft.
 80. The method of claim 64 wherein said step ofenergizing said controller comprises energizing an actuator positionedin a hand grip that generates rotating motion to said clearing member.81. The method of claim 80 wherein said step of inserting a secondworking end comprises providing a negative taper brush at an extreme tipof said clearing member and wherein said negative taper brush comprisesbristles that are wider in diameter at a distal end of said brush thanat a proximal end of said brush.
 82. The method of claim 80 wherein saidactuator generates rotational motion in the range of approximately600-1800 rpm.
 83. The method of claim 80 wherein said step of coupling afirst end of a releasably-securable flexible clearing member to acontroller comprises coupling said clearing member to an output of amotor, said motor output torque being in the range of approximately 20mNm-40 mNm.
 84. The method of claim 80 wherein said step of coupling afirst end of a releasably-securable flexible clearing member to acontroller comprises coupling said clearing member to an output of atorque limiter which is coupled to an output of a motor, said torquelimiter limiting said motor output torque to the range of approximately20 mNm-40 mNm.
 85. The method of claim 80 wherein said step of insertinga second working end comprises providing a first sheath end having portsthat permit irrigation or aspiration at said second working end throughsaid ports when said ports are coupled to irrigation/aspiration sources.86. The method of claim 80 wherein said step of inserting a secondworking end comprises inserting a hollow clearing member that permitsirrigation or aspiration at said second working end.
 87. The method ofclaim 80 wherein said step of inserting a second working end of saidflexible clearing member into an opening in the artificial tubecomprises inserting a second working end that includes a clearing memberstem that is completely exposed in the artificial tube and wherein afirst clearing member stem end is coupled to said actuator thatgenerates said rotating motion.
 88. The method of claim 80 wherein saidstep of energizing said controller comprises driving said clearingmember to experience a plurality of nodal points and wherein a maximumtransverse displacement of said clearing member is approximately 25.4 mmor less.